The present invention relates to knee pads for protecting the patella of a human being and to manufacturing methods for such knee pads.
1. Background of the Invention
Industrial kneepads are used in a variety of occupations that require occasional to continuous kneeling. Typical users of kneepads include baggage handlers, carpenters, roofers, tile installers, and carpet layers. Any person who is required to kneel for an extended period of time runs the risk of injuring his or her kneecap (patella). Some of the common knee injuries (Patellar Subluxation, Knee Contusion, and Bursitis, Chrondromalacia Patella Syndrome) are caused by weight, pressure, and twisting at the knee.
Kneepads are designed to reduce the chance of injury and to provide comfort to the user while kneeling. Typical kneepads are big and awkward and have a tendency to migrate down the legs. The most common kneepads are made of a closed cell foam that is cut into shape and placed in a cloth pouch that is attached to a plastic knee cup. Kneepads are usually fastened with elastic or webbing straps. Kneepads provide padding to the knee while the plastic kneecap provides swivel and sliding action, taking friction off the patella.
2 . Description of the Prior Art
Knee pads are known in the prior art, which consists basically of familiar and obvious structural configurations despite a large number of knee pad designs which have been developed to meet various objectives or requirements.
The present invention is a low-profile, shock absorbent knee pad which offers the patella protection from pressure, weight, and abrasion when kneeling for extended periods.
The invention utilizes two different ploymeric materials to form a knee pad structure. The first material is a pliable yet durable material which form the outer knee shell of the knee pad. The knee shell provides the basic structure of the device. A second, softer material is injected into a recess in the knee shell as an insert. The second, softer material provides a cushioning surface into which the user""s knee can sink when in use. No blown foam is used in the invented knee pad.
The preferred material for the knee insert is a thermoplastic elastomer (TPE), and most preferably Santopreneg which is especially formulated to be used in combination with polyamide or polyurethane for applications where hard/soft combinations are required. The preferred material for the knee shell is a Ethylene Vinyl Acetate (EVA), especially formulated for molding flexible articles.
The knee cup and insert are injection molded in a one step process. These materials and processes permit the design of an extraordinarily flexible and thin knee pad.
The principal object of the present invention is to provide an improved knee pad for use by wearers who are required by their duties to kneel frequently.
A further object of this invention is to provide a method of manufacturing an improved knee pad.